Studies On Desert Rodent Metapopulation In Fragmented Habitats Subjected To Human Disturbances

Recently, Influence of human activities and natural disturbances the habitat of Alxadesert in Inner Mongolia was fragmentized, it was lead to the discontinuous distributionof rondent between habitat patches which had a higher risk of extinction in such smallpatches. Population dynamics and spatial pattern of Mongolian Gerbils were investigatedby mark-and-recapture method from2002to2012. This study was conducted in fourdifferent habitat patches by different use patterns including a prohibited-grazing site, arotational-grazing site, an over-grazing site and a farmland. We had test the populationspatial structure of rodent whether the had the function of metapopulation, and discussthe spatial response mechanism of habitat fragmentation. We will make an attempt toProvide adequate experimental evidence for metapopulation theory. The results showedthat:(1) It was had some differences between rodent patches occupancy, the Merionesunguiculatus patches occupancy was most obvious change in different patches, theCricetulus barabensis comes second, and the others change unconspicuous.The Merionesunguiculatus and Cricetulus barabensis had a significant population turnover, becausethey had extinction risk in different habitat patches but they had possibility ofrecolonization after local extinction. The others turnover is not obvious, or had extinctionand recolonization dynamic in the fewer patches.(2) The density of rodent population had difference in annual, especially, Merionesunguiculatus and Cricetulus barabensis. In this area, Meriones meridianus localpopulation had revealed largely synchronous dynamics between different habitat patchesonly.(3) The Meriones unguiculatus, Cricetulus barabensis, Meriones meridianus andPhodopus roborovskii had shorter residence time and higher turnover rate. Relatively, theAllactaga sibirica, Dipus sagitta and Spermophilus alaschanicus had a longer residencetime and lower turnover rate. The most dispersal individuals were male, but the Dipussagitta were female mainly.(4) The Meriones unguiculatus and Cricetulus barabensis population fulfillsexceptionally well the four conditions of regional persistence of a species as a classicalmetapopulation. Allactaga sibirica and Dipus sagitta was the patchy population in the over grazing area, rotational grazing area and prohibited grazing area.(5) The rodents in this area was a metapopulation of coexistence with multi specieswhich led to the formation of metacommunity as a whole.